Effect of CarMa source (fetal vs. adult) and cell density on mRNA expression of (a) SZP, (b) Col II, (c) Sox-9, and (d) AGC of the encapsulated hMSCs incubated in chondrogenic medium/TGF-β1 supplemented with BMP-7 for 21 days. Groups included 200 million cells/mL in f-CarMa (f-200, solid black) and a-CarMa (a-200, dashed black) hydrogels, 100 million cells/mL in f-CarMa (f-100, solid dark grey) and a-CarMa (a-100, dashed dark grey), 60 million cells/mL in f-CarMa (f-60, solid medium grey) and a-CarMa (a-60, dashed medium grey), and 25 million cells/mL in f-CarMa (f-25, solid light grey) and a-CarMa (a-25, dashed light grey). An asterisk (*) indicates a statistically significant difference (p < 0.05) between the test group and all other groups for a given time point. AGC, aggrecan; Col II, collagen type II; SZP, superficial zone protein.